Enhanced AMPAR-dependent synaptic transmission by S-nitrosylation in the vmPFC contributes to chronic inflammatory pain-induced persistent anxiety in mice.

Chronic pain patients often have anxiety disorders, and some of them suffer from anxiety even after analgesic administration. In this study, we investigated the role of AMPAR-mediated synaptic transmission in the ventromedial prefrontal cortex (vmPFC) in chronic pain-induced persistent anxiety in mice and explored potential drug targets. Chronic inflammatory pain was induced in mice by bilateral injection of complete Freund's adjuvant (CFA) into the planta of the hind paws; anxiety-like behaviours were assessed with behavioural tests; S-nitrosylation and AMPAR-mediated synaptic transmission were examined using biochemical assays and electrophysiological recordings, respectively. We found that CFA induced persistent upregulation of AMPAR membrane expression and function in the vmPFC of anxious mice but not in the vmPFC of non-anxious mice. The anxious mice exhibited higher S-nitrosylation of stargazin (an AMPAR-interacting protein) in the vmPFC. Inhibition of S-nitrosylation by bilaterally infusing an exogenous stargazin (C302S) mutant into the vmPFC rescued the surface expression of GluA1 and AMPAR-mediated synaptic transmission as well as the anxiety-like behaviours in CFA-injected mice, even after ibuprofen treatment. Moreover, administration of ZL006, a small molecular inhibitor disrupting the interaction of nNOS and PSD-95 (20 mg·kg-1·d-1, for 5 days, i.p.), significantly reduced nitric oxide production and S-nitrosylation of AMPAR-interacting proteins in the vmPFC, resulting in anxiolytic-like effects in anxious mice after ibuprofen treatment. We conclude that S-nitrosylation is necessary for AMPAR trafficking and function in the vmPFC under chronic inflammatory pain-induced persistent anxiety conditions, and nNOS-PSD-95 inhibitors could be potential anxiolytics specific for chronic inflammatory pain-induced persistent anxiety after analgesic treatment.

Diosmin Alleviates Venous Injury and Muscle Damage in a Mouse Model of Iliac Vein Stenosis.

Chronic venous disease (CVD) is a progressive inflammatory disease that increases in prevalence with age. Elucidating the underlying molecular mechanism of CVD development is essential for disease prevention and treatment. This study constructed a mouse model of iliac vein stenosis to explore the mechanism of the CVD disease progression, and diosmin was administered as a positive control (as recommended by clinical practice). The mouse model was established successfully with iliac vein stenosis, leading to the expansion of the intercellular space and venous leakage. Conversely, micronized diosmin showed a dose-dependent therapeutic effect for these manifestations. Concerning the mechanism, iliac vein stenosis caused an inflammatory response in veins, while diosmin suppressed this increase. Furthermore, RNA sequencing analysis indicated that diosmin significantly improved muscle function through actin filament organization and muscle contraction. These results indicated that the mouse model of iliac vein stenosis is a reliable model to study venous diseases. Furthermore, the dose-dependent therapeutic effect of diosmin on stenosis (without toxic side-effects) suggests greater protection against venous diseases at higher doses of diosmin.